<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        function unique(oldArr) {
            var newArry = []
            for (i = 0; i < oldArr.length; i++) {
                if (newArry.indexOf(oldArr[i]) === -1) {
                    newArry.push(oldArr[i])
                }
            }
            return newArry
        }
        arr = unique(['a','c','d','a','e','b','f','c'])
        console.log(arr);
    </script>
</body>
</html>